feat: add double down feature to blackjack game

This commit is contained in:
Jan-Marlon Leibl 2025-03-27 15:40:26 +01:00
parent d90fcdcf1e
commit d2b22b561d
Signed by: jleibl
GPG key ID: 300B2F906DC6F1D5
7 changed files with 190 additions and 61 deletions

View file

@ -77,6 +77,23 @@ public class BlackJackGameController {
return ResponseEntity.ok(blackJackService.stand(game));
}
@PostMapping("/blackjack/{id}/doubleDown")
public ResponseEntity<Object> doubleDown(@PathVariable Long id, @RequestHeader("Authorization") String token) {
Optional<UserEntity> optionalUser = userService.getCurrentUser(token);
if (optionalUser.isEmpty()) {
return ResponseEntity.notFound().build();
}
UserEntity user = optionalUser.get();
BlackJackGameEntity game = blackJackService.getBlackJackGame(id);
if (game == null || !Objects.equals(game.getUserId(), user.getId())) {
return ResponseEntity.notFound().build();
}
return ResponseEntity.ok(blackJackService.doubleDown(game));
}
@PostMapping("/blackjack/start")
public ResponseEntity<Object> createBlackJackGame(@RequestBody @Valid CreateBlackJackGameDto createBlackJackGameDto, @RequestHeader("Authorization") String token) {
Optional<UserEntity> optionalUser = userService.getCurrentUser(token);

View file

@ -14,17 +14,15 @@ import java.util.Random;
public class BlackJackService {
private final BlackJackGameRepository blackJackGameRepository;
private final UserRepository userRepository;
private final Random random = new Random();
public BlackJackService(BlackJackGameRepository blackJackGameRepository, UserRepository userRepository) {
this.blackJackGameRepository = blackJackGameRepository;
this.userRepository = userRepository;
}
private final Random random = new Random();
public BlackJackGameEntity getBlackJackGame(Long id) {
Optional<BlackJackGameEntity> optionalBlackJackGame = blackJackGameRepository.findById(id);
return optionalBlackJackGame.orElse(null);
return blackJackGameRepository.findById(id).orElse(null);
}
@Transactional
@ -32,88 +30,146 @@ public class BlackJackService {
BlackJackGameEntity game = new BlackJackGameEntity();
game.setUser(user);
game.setBet(betAmount);
initializeDeck(game);
for (int i = 0; i < 2; i++) {
CardEntity playerCard = drawCardFromDeck(game);
playerCard.setCardType(CardType.PLAYER);
game.getPlayerCards().add(playerCard);
}
CardEntity dealerCard = drawCardFromDeck(game);
dealerCard.setCardType(CardType.DEALER);
game.getDealerCards().add(dealerCard);
BlackJackState state = handleState(game, user);
game.setState(state);
userRepository.save(user);
dealInitialCards(game);
game.setState(getState(game));
deductBetFromBalance(user, betAmount);
return blackJackGameRepository.save(game);
}
@Transactional
public BlackJackGameEntity hit(BlackJackGameEntity game) {
game = blackJackGameRepository.findById(game.getId()).orElse(game);
game = refreshGameState(game);
if (game.getState() != BlackJackState.IN_PROGRESS) {
return game;
}
CardEntity drawnCard = drawCardFromDeck(game);
drawnCard.setCardType(CardType.PLAYER);
game.getPlayerCards().add(drawnCard);
game.setState(handleState(game, game.getUser()));
if (game.getState() == BlackJackState.PLAYER_WON) {
updateUserBalance(game, true);
} else if (game.getState() == BlackJackState.PLAYER_LOST) {
updateUserBalance(game, false);
}
dealCardToPlayer(game);
updateGameStateAndBalance(game);
return blackJackGameRepository.save(game);
}
@Transactional
public BlackJackGameEntity stand(BlackJackGameEntity game) {
game = blackJackGameRepository.findById(game.getId()).orElse(game);
game = refreshGameState(game);
if (game.getState() != BlackJackState.IN_PROGRESS) {
return game;
}
while (calculateHandValue(game.getDealerCards()) < 17) {
CardEntity dealerCard = drawCardFromDeck(game);
dealerCard.setCardType(CardType.DEALER);
game.getDealerCards().add(dealerCard);
}
dealCardsToDealerUntilMinimumScore(game);
determineWinnerAndUpdateBalance(game);
return blackJackGameRepository.save(game);
}
@Transactional
public BlackJackGameEntity doubleDown(BlackJackGameEntity game) {
game = refreshGameState(game);
if (game.getState() != BlackJackState.IN_PROGRESS || game.getPlayerCards().size() != 2) {
return game;
}
UserEntity user = getUserWithFreshData(game.getUser());
BigDecimal additionalBet = game.getBet();
if (user.getBalance().compareTo(additionalBet) < 0) {
return game;
}
deductBetFromBalance(user, additionalBet);
game.setBet(game.getBet().add(additionalBet));
dealCardToPlayer(game);
updateGameStateAndBalance(game);
if (game.getState() == BlackJackState.IN_PROGRESS) {
return stand(game);
}
return game;
}
private BlackJackGameEntity refreshGameState(BlackJackGameEntity game) {
return blackJackGameRepository.findById(game.getId()).orElse(game);
}
private UserEntity getUserWithFreshData(UserEntity user) {
return userRepository.findById(user.getId()).orElse(user);
}
private void dealInitialCards(BlackJackGameEntity game) {
for (int i = 0; i < 2; i++) {
dealCardToPlayer(game);
}
dealCardToDealer(game);
}
private void dealCardToPlayer(BlackJackGameEntity game) {
CardEntity card = drawCardFromDeck(game);
card.setCardType(CardType.PLAYER);
game.getPlayerCards().add(card);
}
private void dealCardToDealer(BlackJackGameEntity game) {
CardEntity card = drawCardFromDeck(game);
card.setCardType(CardType.DEALER);
game.getDealerCards().add(card);
}
private void dealCardsToDealerUntilMinimumScore(BlackJackGameEntity game) {
while (calculateHandValue(game.getDealerCards()) < 17) {
dealCardToDealer(game);
}
}
private void updateGameStateAndBalance(BlackJackGameEntity game) {
game.setState(getState(game));
if (game.getState() == BlackJackState.PLAYER_WON) {
updateUserBalance(game, true);
} else if (game.getState() == BlackJackState.PLAYER_LOST) {
updateUserBalance(game, false);
}
}
private void determineWinnerAndUpdateBalance(BlackJackGameEntity game) {
int playerValue = calculateHandValue(game.getPlayerCards());
int dealerValue = calculateHandValue(game.getDealerCards());
if (dealerValue > 21 || playerValue > dealerValue) {
game.setState(BlackJackState.PLAYER_WON);
updateUserBalance(game, true);
} else if (playerValue < dealerValue) {
game.setState(BlackJackState.PLAYER_LOST);
updateUserBalance(game, false);
} else {
game.setState(BlackJackState.DRAW);
updateUserBalance(game, false);
updateUserBalance(game, false); // For draw, player gets their bet back
}
return blackJackGameRepository.save(game);
}
private void deductBetFromBalance(UserEntity user, BigDecimal betAmount) {
user.setBalance(user.getBalance().subtract(betAmount));
userRepository.save(user);
}
@Transactional
private void updateUserBalance(BlackJackGameEntity game, boolean isWin) {
UserEntity user = game.getUser();
user = userRepository.findById(user.getId()).orElse(user);
BigDecimal balance = user.getBalance();
UserEntity user = getUserWithFreshData(game.getUser());
BigDecimal betAmount = game.getBet();
BigDecimal balance = user.getBalance();
if (isWin) {
balance = balance.add(betAmount.multiply(BigDecimal.valueOf(2)));
}
else if (game.getState() == BlackJackState.DRAW) {
} else if (game.getState() == BlackJackState.DRAW) {
balance = balance.add(betAmount);
}
@ -144,7 +200,7 @@ public class BlackJackService {
return game.getDeck().removeFirst();
}
private BlackJackState handleState(BlackJackGameEntity game, UserEntity user) {
private BlackJackState getState(BlackJackGameEntity game) {
int playerHandValue = calculateHandValue(game.getPlayerCards());
if (playerHandValue == 21) {
@ -155,14 +211,14 @@ public class BlackJackService {
int dealerHandValue = calculateHandValue(game.getDealerCards());
if (dealerHandValue == 21) {
return BlackJackState.STANDOFF;
return BlackJackState.DRAW;
} else {
BigDecimal blackjackWinnings = game.getBet().multiply(new BigDecimal("1.5"));
UserEntity user = getUserWithFreshData(game.getUser());
user.setBalance(user.getBalance().add(blackjackWinnings));
return BlackJackState.PLAYER_BLACKJACK;
}
} else if (playerHandValue > 21) {
user.setBalance(user.getBalance().subtract(game.getBet()));
return BlackJackState.PLAYER_LOST;
}